1) Field of the Invention
The present invention relates to a method and an apparatus for computer lock management, and computer product that prevent a computer from becoming unable to recover from a lock state, and that allow a user to carry out lock processing for the computer safely.
2) Description of the Related Art
Conventionally, when a user of a computer is away from the desk, a locking mechanism known as workstation lock is used to prevent the computer from being used by other users illegally.
The workstation lock hides a work screen that is displayed when a user logs on to an operating system, and displays only a dialogue box to input a password or the like that is required for releasing the lock. Thus, the workstation lock restricts operations other than input in the dialogue box, and prevents illegal use by other users.
For example, in an operating system like Microsoft Windows (registered trademark), a module called a Graphical Identification and Authentication (GINA) executes the process for the workstation lock. This GINA module is of plug-in type, and by developing a security module conforming to specifications for the GINA and incorporating the security module in the operating system, the security module controls the GINA.
On the other hand, use of a storage device like a smart card or a Universal Serial Bus (USB) memory key on a computer has become popular. Thus, application software or the like, with which a user can confirm information stored in the smart card or the like on a personal computer, has been developed (see http://www.sony.co.jp/Products/felica/pcrw/sfcard_dl.html, Sony Corporation, “PaSoRi (RC-S310) Application SFCard Viewer”, [online], [retrieved on Apr. 1, 2004]).
A security function is added to the storage device to use the storage device as an authentication device that performs user authentication, whereby illegal use of a computer is prevented.
For example, when a smart card is pulled out from a smart card reader, which reads information stored in the smart card, the workstation is automatically locked. The workstation lock cannot be released until the smart card is inserted again, and the authentication process is performed based on authentication information stored in the smart card.
However, the conventional technique disclosed on the Web page of Sony Corporation has a problem in that, if the storage device is pulled out in a state in which access to the storage device is occupied by a certain application program, even if the storage device is inserted again, the storage device is not recognized and the workstation lock cannot be released.
This is because a program for accessing the storage device does not cope with multiple access by plural application programs. Therefore, an error occurs if the storage device receives a request for access from a program other than the application program occupying access to the storage device.
When the workstation lock cannot be released, there is no way for releasing the workstation lock but to forcibly disconnect a power supply of a computer. Thus, it is likely that a document under preparation is destroyed, or data stored in the computer is damaged.